Characterization of carbon/carbon composite/Ti6Al4V joints brazed with graphene nanosheets strengthened AgCuTi filler
Characterization of carbon/carbon composite/Ti6Al4V joints brazed with graphene nanosheets strengthened AgCuTi filler
复制标题
石墨烯纳米片增强 AgCuTi 填料钎焊碳/碳复合材料/Ti6Al4V 接头的表征
DOI：
10.1016/j.ceramint.2017.09.049
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发表时间：
2017-12-15
影响因子：
5.2
通讯作者：
Feng, Jicai
中科院分区：
文献类型：
--
作者：
Zhou, Yinghao;Liu, Duo;Feng, Jicai
采用石墨烯纳米片增强AgCuTi钎料（AgCuTiG）成功地钎焊了C/C复合材料和Ti6 Al 4V合金（wt%）。采用球磨法将低CTE、高强度的石墨烯纳米片分散到AgCuTi填料中。通过透射电子显微镜（TEM）等多种分析手段对界面微观结构进行了系统的表征。结果表明，在880 ℃钎焊10 min时，接头界面组织为（Ti6 Al 4V/扩散层/Ti 2Cu + TiCu + Ti 3Cu 4 + TiCu 4/GNSs + TiCu + TiC + Ag（s，s）+ Cu（s，s）/TiC/C/C复合材料）层状结构。钎焊接头界面组织和力学性能随温度的升高而发生显著变化。高温促进了TiCu和TiC相的生长，并附着在GNS上。随着温度的升高，扩散层和主反应层增厚，而焊缝厚度减小。在900 ℃钎焊10 min时，接头的剪切强度最大为30.2 MPa。GNS减小了脆性反应层的厚度，促进了焊缝中TiCu和TiC相的形成，起到了强化作用，降低了接头的热膨胀系数失配。文中还对断裂模式进行了讨论。
Carbon/carbon (C/C) composite and Ti6Al4V alloy (wt%) were successfully brazed with graphene nanosheets strengthened AgCuTi filler (AgCuTiG). Graphene nanosheets (GNSs) with low CTE and high strength were dispersed into AgCuTi filler by ball milling. The interfacial microstructure was systematically characterized by varieties of analytical means including transmission electron microscopy (TEM). Results show that typical interfacial microstructure of the joint brazed at 880 degrees C for 10 min is a layer structure consisting of (Ti6Al4V/diffusion layer/Ti2Cu + TiCu + Ti3Cu4 + TiCu4/GNSs + TiCu + TiC + Ag(s,s) + Cu(s,s)/TiC/C/C composite). The interfacial microstructure and mechanical properties of brazed joints changed significantly as temperature increased. High temperature promoted the growth of TiCu and TiC phases, which were attached to GNSs. Meanwhile, the diffusion layer and primary reaction layers thickened as temperature increased, while the thickness of brazing seam decreased. The maximum shear strength of 30.2 MPa was obtained for the joint brazed at 900 degrees C for 10 min. GNSs decreased the thickness of brittle reaction layers and promoted the formation of TiCu and TiC phases in brazing seam, which caused the strengthening effect and decreased the CTE mismatch of brazed joints. The fracture modes are also discussed in this paper.